The volume of an adult's stomach ranges from about 50 mL when empty to 1 L when full.If its volume is 500 mL and its contents have a pH of 2, how many moles of H+ does it contain?

Answer 1

pH = -log(H^+).
Solve for (H^+) and the answer is in molarity which is moles/L.
Then moles = M x L = ??

Answer 2

You are given pH which is (-log[H^+] ). so first you take 10^-2 to get the Molarity of [H^+], then you convert 500 mL to Liters so divide 500 by 1000. Finally you take Molarity times volume in liters to get moles of H^+.

10^-2 = .01

500/1000 = .5

.01 * .5 = 5*10^-3 = Moles of H^+ ions.